Well done you've taken your first steps down the slippery slope to DIY obsesesion, lol! See it's not so bad. The app is great, makes it much easier. Personally I don't get on with pipettes, syringes are much easier but using the same measuring thing for all ingredients is the most important thing. Now try not to vape it all before it's steeped (I can't talk, I always give in )
Hope it tastes great. Do expect a few Frankenjuice disasters along the way - but they get less frequent as you learn your way around flavours. I too prefer syringes to pipettes. I have recently started using one 1 ml syringe per flavour and it speeds up both the mixing and cleaning and saves on vodka and sterile wipes for mid mix flavour concentrate swaps.