Back in stock apps for Shopify: what the pricing actually costs at scale
A line-by-line pricing teardown of Swym, Appikon, Amp, STOQ, Notify!, and Kbite, plus what per-subscriber vs. per-send metering means for your actual monthly bill as your list grows.
07/03/2026
Every back in stock app publishes a pricing page, and almost none of them make it easy to answer the question that actually matters: what will this cost once my list and my restock cadence look like a real, growing store instead of the small numbers on the free tier. This is a line-by-line teardown of what six of the category’s most-reviewed apps charge, as listed on their Shopify App Store pages in July 2026, plus a worked example so the numbers mean something concrete.
What gets metered, and why it matters
Before comparing tiers, it is worth naming the two different things these apps meter, because they produce very different bills as you grow:
- Per-send metering counts notification emails (and sometimes SMS) actually sent. Your subscriber list can be unlimited or very large, and you only pay for the alerts that go out when something restocks.
- Per-preorder or per-action metering counts a different unit, such as preorders placed or wishlist actions, often blended with a send allowance in the same tier, which makes tiers harder to compare apples to apples across apps.
A few apps also carry per-unit overage charges once you exceed a tier’s limit, separate from the flat monthly fee. That is a materially different pricing shape than a hard cap that just holds sends until you upgrade, and it is worth knowing which one you are looking at before you commit.
The pricing, tier by tier (July 2026, as listed)
Swym Back in Stock Alerts. Starter $19.99/mo (up to 1,000 alert requests/mo, $199.99/yr annual); Pro $59.99/mo (up to 10,000/mo, $599.99/yr); Premium $99.99/mo (up to 25,000/mo, $999.99/yr). No free tier as of 2026. Swym removed its previously free entry option, a change its own recent App Store reviews describe directly, with one reviewer noting the entry plan “costs almost as much as Shopify itself.”
Appikon - Back In Stock. Free (10 emails/mo); Starter $19.99/mo (300/mo, $192/yr); Pro $29.99/mo (1,000/mo, $287.90/yr); Premium $49.99/mo (3,000/mo, $470/yr). SMS is metered separately at $0.05 to $0.40 per message depending on character count.
Amp Back in Stock | PreOrder. Free (10 notifications/mo, unlimited signups); Lite $19/mo (50 notifications, 100 preorders); Startup $29/mo (100 notifications, 500 preorders); Small Business $49/mo (500 notifications, unlimited preorders). SMS flat at $0.015/message. Notice the shape here: notification allowances stay low even as price climbs, because each tier is bundling in a preorder allowance too.
Preorder, Back In Stock - STOQ. Free (10 preorders/mo, 30 emails/mo); Lite $10/mo (100 preorders, 1,000 email/SMS); Pro $29/mo (400 preorders, 2,000 email/SMS); Unlimited $69/mo (unlimited preorders and email/SMS). 14-day trial on paid tiers.
Notify! Back in Stock|PreOrder. Lite Free (10 restock notifications, 5 preorders, 50 wishlist actions); Kickstart $9.90/mo ($95/yr); Starter $19.90/mo ($191/yr); Standard $39.90/mo ($383/yr, 1,500 preorders/alerts, 10,000 wishlist actions). Notify! also charges overage on preorders at $0.15 to $0.20/unit above the plan limit, a per-unit fee on top of the subscription, which its own reviews describe as “pricing confusion and unexpected charges.”
Back In Stock, Notify Me: Kbite. Free (30 emails/mo, unlimited subscribers); Basic $5/mo (500 email/mo); Starter $9/mo (2,500 email/mo, batch delivery); Pro $19/mo (5,000 email/mo, custom integrations). SMS from $0.02/message (US). This is the cheapest reputable player in the category by a wide margin. Its $5 to $19/mo range sits well under Swym’s and Appikon’s $19.99+ entry points, and its reviews explicitly cite price as a reason for choosing it.
Side by side
| App | Free tier | Entry paid tier | Mid tier | Top listed tier | Overage/unit fees |
|---|---|---|---|---|---|
| Swym | None | $19.99/mo, 1,000 alerts | $59.99/mo, 10,000 | $99.99/mo, 25,000 | None disclosed |
| Appikon | 10 emails/mo | $19.99/mo, 300/mo | $29.99/mo, 1,000/mo | $49.99/mo, 3,000/mo | SMS $0.05–$0.40/msg |
| Amp | 10 notif./mo | $19/mo, 50 notif. | $29/mo, 100 notif. | $49/mo, 500 notif. | SMS $0.015/msg flat |
| STOQ | 10 preorders + 30 emails/mo | $10/mo, 1,000 email/SMS | $29/mo, 2,000 email/SMS | $69/mo, unlimited | None disclosed |
| Notify! | 10 notif. + 5 preorders/mo | $9.90/mo | $19.90/mo | $39.90/mo, 1,500 preorders/alerts | Preorder overage $0.15–$0.20/unit |
| Kbite | 30 emails/mo, unlimited subs | $5/mo, 500 email/mo | $9/mo, 2,500 email/mo | $19/mo, 5,000 email/mo | SMS from $0.02/msg |
| Kelso | 50 sends/mo, unlimited subs | $14/mo, 750 sends | $29/mo, 3,000 sends | $59/mo, 10,000 sends | None |
Pricing as listed on each app’s Shopify App Store page, July 2026. Check the live listing for current numbers before you commit, since pricing in this category changes often enough that Swym’s own free-tier removal is the clearest recent example.
A worked example: 2,000 subscribers, 8 restocks a month
Take a mid-size store: 2,000 total back in stock subscribers spread across a catalog of products and variants, restocking roughly 8 times a month. Not every subscriber gets notified on every restock. A subscriber who is waiting on one out-of-stock hoodie in one color does not hear anything when a completely different product comes back. For this example, assume each restock event notifies an average of 25 subscribers (a reasonable middle case for a catalog where waitlist demand is spread across many SKUs rather than concentrated in one). That works out to roughly 200 sends a month.
At 200 sends/month:
- Kbite’s Basic ($5/mo, 500 email/mo) comfortably covers this, with room to more than double before upgrading.
- STOQ’s Free tier (30 emails/mo) does not cover it; STOQ’s Lite ($10/mo, 1,000 email/SMS) does, with significant headroom.
- Appikon’s Free tier (10 emails/mo) does not come close; Appikon’s Starter ($19.99/mo, 300/mo) covers it.
- Amp’s Free tier (10 notifications/mo) does not cover it. Even Amp’s Lite ($19/mo, 50 notifications) falls short of 200 sends, as does Amp’s Startup tier ($29/mo, 100 notifications), so a store at this volume would need Amp’s Small Business tier ($49/mo, 500 notifications) to have real headroom.
- Notify!’s Free tier (10 restock notifications/mo) does not cover it. Notify!’s published tiers step up to Standard ($39.90/mo) before listing an explicit alert cap again (1,500 preorders/alerts/mo), so a store at this volume should confirm the exact Kickstart and Starter caps on the live listing before assuming either covers 200 sends/mo.
- Swym has no free tier; its Starter ($19.99/mo, 1,000 alert requests/mo) covers 200 sends with substantial headroom, but it is the most expensive entry point in this comparison for a store at this volume.
- Kelso’s Free tier (50 sends/mo) does not cover 200 sends; Kelso’s Starter ($14/mo, 750 sends) does, with headroom for the store to nearly quadruple its restock volume before needing to upgrade.
The spread across these six apps at the exact same usage level, roughly $5 to $30 a month depending which app you picked, is the real finding here. Two stores with identical subscriber counts and identical restock cadence can land on bills that differ by 4 to 6x, purely because of which app’s tier structure they happened to land on, not because of any difference in the volume of email actually being sent.
What to actually check before you commit
- Is the free tier real, or a trial in disguise? A free tier with 10 sends a month is not usable at any real volume; it exists to let you try the widget, not to run a program on. Kbite’s 30/mo and STOQ’s 30/mo free allowances are more workable starting points than a 10/mo cap.
- Does the tier bundle sends with an unrelated unit (preorders, wishlist actions)? If a tier’s headline number covers preorders and alerts together, your effective alert allowance is lower than the number on the pricing page suggests. Read the fine print on what counts against the cap.
- Are there per-unit overage fees, or does the app just hold sends until you upgrade? A flat monthly fee with a hard cap is predictable. A monthly fee plus a per-unit overage charge (as with Notify!’s preorder overage) means your bill can move even when your subscription tier does not, and it is the exact pattern that shows up as “unexpected charges” in that app’s own review history.
- What happens to your subscriber list if you go over your limit or downgrade? Some apps meter subscriber count itself, not just sends, which means a fast-growing waitlist can force an upgrade even in a month with no restocks at all.
The short version
Pricing in this category is not standardized enough to compare on sticker price alone. The same 200 sends a month can cost anywhere from about $5 to $30 depending on the app, and the real variables to check are what unit gets metered, whether the free tier is usable at real volume, and whether overage is a hard hold or a per-unit charge. Run your own numbers, your subscriber count times your restock frequency times your average notified-per-restock, against each app’s actual tier table before deciding, rather than against the headline price on the pricing page.