I have a lot of apps for drawing and sketching on my iPad. I think I'm hoping that I will find that ONE app that will make me a great artist. Lol! As much as there's an app for pretty much everything, I really doubt there's an app for that. It's just going to take a lot of practice drawing and drawing and drawing. It's like knitting, you can't knit one row and expect to be perfect.
Sketchclub - great for all around sketching. It has text and vector drawing capabilities. Import to other apps with transparency for more editing. Great to use as a photoediting app as well. Great friendly user interface and easy to learn. Files can be easily imported through iTunes or photoshop for editing and printing.
Artrage - it's a great app but the lagging drives me crazy. This might be my second favourite app if it wasn't for the lagging. Love all the different canvas textures. If you don't mind the lag, you can do wonderful work on this app. I like the watercolour on this app, though. It's an app that you need to take some time to learn.
Procreate - love the brushes and the ease you can create fabulous brushes. Importing them to Sketchclub is a breeze. Import can be done with tranparency if you turn off the main colour on the background layer. Easy to import to iTunes and photoshop for more indepth editing and printing. The transform is not as smooth as Sketchclub.
Sketchbook Pro - when I first got it, it found it hard to learn. I didn't find it user friendly for me. This was my first drawing/painting app and you really need to know how to adjust your brushes. Over the year, the various upgrades made it much more user friendly...or maybe I'm starting to understand how to make adjustments better. I don't know...it is a nice app and I use it occasionally but for now, I'm so much more comfortable with the other apps that I rarely use this one.
I have close to 10 drawing/painting apps. The others are much smaller apps and do a fraction of what these ones do. I'll play around with them once in a while.
No matter which app you use, the important thing is to get to know it and what it can do. From what I see on the Internet with the work other people put out, they're all pretty good. It's like knitting needles...it doesn't really matter if you use wood or bamboo or metal or plastic, as long as you're comfortable with the tool you're using, it's all good.
Edited to add - moments after I posted this, Procreate came out with a kick-ass update. Honestly, they're all great apps...Sketchclub is still my go-to app but love all the others too.