I have tried all sorts of productivity apps through the years and most, no actually ALL I have ended up deleting! But when I came across Forest curiosity got the best of me and I downloaded it, and I can honestly say it has boosted my work ethic and focus a hella ton! There is something just super motivating and rewarding seeing your little forest grow as you get more and more work done. It's also a great app for anyone who struggles with smart phone addiction!
Take a look and see if it's your kinda thing!