Stacker - No-Code internal tools powered by Airtable, GSheets + more
Cold Turkey - Cold Turkey is a free productivity program that you can use to temporarily block distractions so that you can get your work done!
Retool - Build custom internal tools in minutes.
Stay Focused - More suitable with Google Chrome, this service enables you ensure you do not waste precious time on updating Facebook status or chatting with people.
ToolJet - Open-source alternative for Retool
Freedom.to - Freedom is a productivity hack that lets you block apps, websites or the entire Internet on iPhones, iPads, Windows and Mac computers.