Ayden:
No application needed: No
Transparent pricing: Yes
No monthly fee: Yes
Reasonable per-transaction percentages: Yes (complex table depending on where the payment is coming from)
No bad reputation: Yes
Targets micro businesses: Unclear
Payment button+IPN API: Yes (https://docs.adyen.com/online-payments/web-components, https://docs.adyen.com/development-resources/webhooks)
Local payments API: Yes (https://docs.adyen.com/online-payments/api-only)
Reasonably modern website: Yes
Reasonably stable business: Yes
International: Yes
No bank merchant account needed: Yes
Supports subscriptions: Yes
Supported by PHP Omnipay library: No