An app that has recently been introduced to Android is Tayasui Sketches. This app has been available for IOS for some time now, but not for Android until recently. The Android version has ten tools: a mechanical pencil, a pen, a marker, a brush pen, a watercolor brush, a paint brush, an airbush, a crayon, a pattern brush, and an eraser. This app has three layers with merge and multiply functions. You can pinch to zoom in or undo, redo, or pan with two fingers. You can even start a new picture by sliding to the left with three fingers. The brushes have different tips and you can set the size and opacity. When you double tap the eraser, it erases the whole canvas. You can download a free version of this app, but to unlock all the features requires an in app purchase of around $2.15 per item. Overall, this is a very good inking app and you can make some nice pen and ink style drawings with it. I think the IOS version has a recording function, more brushes, and a few more functions than the Android version has.
Here is the UI.