The apps I use for my coloring are 24fps and prequel.

If you want my coloring comment on one of my videos (Coloring tut) and I will put it here!

I use a app called fonts, it gives me some cool symbols like: シ︎㋛︎ఌ︎ꨄ︎❦︎☀︎︎☹︎☻︎☺︎︎✞︎✔︎☏︎𓆉︎❥︎♥︎❣︎❤︎♫︎✰☆✩𖦹☢︎︎☼︎᯽✫۞𖣔⍟𖣘☦︎❀❄︎❁᯾✪⁂𑁍᪥𖧷, and many more!

I made my own theme, if you want to make your own theme you can use a app called vont, it makes making themes / putting themes on your videos very easy!