This app was mentioned in 2 comments, with an average of 1.00 upvote
There's a simple app for Madcow 5x5 which I love using. It does all the calculations for you. Though it's specifically for that program, and could be too similar to SL 5x5 for you :P
https://play.google.com/store/apps/details?id=com.ionicframework.madcow920502&hl=en
https://play.google.com/store/apps/details?id=com.ionicframework.madcow920502 Found this today. Not as great as the SL app, but it is an app. I still think the SL 5x5 app should just have an option to transition to madcow and even at some point recommend when to switch when you plateau with squats.