Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

iA Writer - Minimal Design, Maximum Focus

Solo - Personal kanban boards hosted on your own server

MacDown - MacDown is an open source Markdown editor for OS X, released under the MIT License.

Cash App - The easy way to send, spend, bank, and invest.

MWeb - Pro Markdown writing, note taking and static blog generator