Burst FSA/HSA vs Flex, Pay With HSA/FSA
Two Shopify apps, side by side: detected stores, momentum, reviews, plans, listed features and who runs each. Store counts as of Nov 13, 2026 for Burst FSA/HSA, Nov 1, 2026 for Flex, Pay With HSA/FSA.
The short answer
Head to head
Momentum
New reviews each month
Review pace is the clearest public read on how fast an app is winning new merchants.
Standard
Coverage counts what each App Store listing names. Every feature, checked off app by app, is in Shoplist.
See every featureLet shoppers use their FSA/HSA dollars without changing how they check out. Burst identifies eligible products in your catalog, shows shoppers an eligibility badge on product pages and at checkout, and gives them what they need to claim reimbursement from their FSA/HSA account after purchase. Compliance is handled by Burst. Works with express checkout and recurring orders.
Flex allows merchants that qualify to accept HSA/FSA as a payment option directly in the checkout flow.
- Express Checkout Compatible – Works with your store's express checkout buttons.
- Recurring Orders Supported – Native FSA/HSA support on repeat purchases.
- Automated Compliance Engine – Reimbursements + LMNs managed post-purchase.
- Accept HSA/FSA payments directly in the checkout flow
- Auto-substantiate during checkout
- Qualify your product with a Letter of Medical Necessity
All the numbers
Every figure, side by side
A green dot marks the app ahead on a measured figure. Estimates, gaps and apps that leave no storefront trace never take the lead.
Adoption
| Measure | ||
|---|---|---|
| Detected stores | Not published | Not published |
| Net store change, 28 days | 0 | 0 |
| Stores added, 28 days | Not enough data | Not enough data |
| Big-brand share | Not enough data | Not enough data |
| Top store categories | Not published | Not published |
| Top store countries | Not published | Not published |
Reviews
| Measure | ||
|---|---|---|
| App Store rating | Not published | 5.0 ★ |
| App Store reviews | Not published | 7 |
| New reviews, 28 days | Not enough data | Not enough data |
| Reviewers a year or more in | Not enough data | Not enough data |
Pricing
| Measure | ||
|---|---|---|
| Free plan | Not listed | Not listed |
| Lowest paid monthly plan | No monthly plan listed | No monthly plan listed |
| Longest free trial | Not listed | Not listed |
| Plans listed | 1 | Not published |
Listing
| Measure | ||
|---|---|---|
| Shopify category rank | Not enough data | Not enough data |
| Shopify App Charts | Not on this week’s charts | Not on this week’s charts |
| Built for Shopify | No | No |
| Launched | Nov 13, 2026 | Nov 15, 2023 |
| Languages | 1 | 1 |
| Developer | Burst Group, Inc. | Flex |
FAQ
Burst FSA/HSA and Flex, Pay With HSA/FSA: common questions
- Where does this comparison’s data come from?
- Shoplist crawls Shopify storefronts to detect which apps each store runs, and reads each app’s Shopify App Store listing for reviews, pricing, features and integrations. Store counts are as of Nov 13, 2026 for Burst FSA/HSA, Nov 1, 2026 for Flex, Pay With HSA/FSA; estimated figures are labeled.
How Shoplist compares apps
Store counts come from Shoplist’s crawl of Shopify storefronts, which detects the apps each store runs; they are as of Nov 13, 2026 for Burst FSA/HSA, Nov 1, 2026 for Flex, Pay With HSA/FSA. Reviews, ratings, plans, features and integrations come from each app’s Shopify App Store listing. 28-day figures are labeled when estimated, and a figure that is missing or estimated never decides who leads. Read the methodology.