We apologize for the instability of composr.app and appreciate your patience. We are working on the statistics addon and trying to find an optimal way to store and render data. Unfortunately, we have yet to find a solution that can handle the traffic (and therefore, tens of millions of statistical records) of composr.app. We're working hard on one.
ProPay:
No application needed: No
Transparent pricing: Yes
No monthly fee: No
Reasonable per-transaction percentages: Yes (2.4%)
No bad reputation: Yes
Targets micro businesses: Yes
Payment button+IPN API: Yes (https://www.propay.com/en-US/Documents/API-Docs/ProtectPay-PMI-Hosted-Payment-Page-Manual)
Can followup further transactions with https://www.propay.com/en-US/Documents/API-Docs/ProtectPay-API-Manual-REST
Local payments API: Yes (https://www.propay.com/en-US/Documents/API-Docs/ProPay-API-Manual-REST)
Reasonably modern website: Yes
Reasonably stable business: Yes
International: Yes
No bank merchant account needed: Yes
Supports subscriptions: Not really (have to use ProtectPay to charge followup transactions ourselves)
Supported by PHP Omnipay library: No
No application needed: No
Transparent pricing: Yes
No monthly fee: No
Reasonable per-transaction percentages: Yes (2.4%)
No bad reputation: Yes
Targets micro businesses: Yes
Payment button+IPN API: Yes (https://www.propay.com/en-US/Documents/API-Docs/ProtectPay-PMI-Hosted-Payment-Page-Manual)
Can followup further transactions with https://www.propay.com/en-US/Documents/API-Docs/ProtectPay-API-Manual-REST
Local payments API: Yes (https://www.propay.com/en-US/Documents/API-Docs/ProPay-API-Manual-REST)
Reasonably modern website: Yes
Reasonably stable business: Yes
International: Yes
No bank merchant account needed: Yes
Supports subscriptions: Not really (have to use ProtectPay to charge followup transactions ourselves)
Supported by PHP Omnipay library: No