I've just got a nice hardback notebook that I write everything down in, including the fuck-ups and the nopes. Any alterations, comments, notes and general meanderings go in too. It's starting to look a bit like Grandma's cookbook
I use Juice Calculator; http://diyjuicecalculator.com does everything I need except keep track of how much juice I've made, that gets kept in a spreadsheet.
I found a free app online called Vape Tool - does coil building stuff like steam engine but also has a really good eliquid section and ability to save recipes/mixes... I think with the premium version you can even keep full inventory of your concentrates and set up notifications for when you are running low as it keeps track of what you use in each mix (but i just stick with the free version)