The latest version of ARIS Grid & Raster Editor for ArcMap (https://www.aris.nl/gridrastereditor_arcmap) will let you do a limited number of edits in an edit session for free during the trial period. These edits are saved instantly so you can really check out whether it suits your work.
![gridrastereditor_freehand.png](http://www.aris.nl/media/aris/images/gridrastereditor_freehand.png)
In this tool many common drawing tools can be used on raster data like: pencil/freehand, line, polygon, paintcan, replace specific values, selection area.
Besides the ESRI GRID format now also many other raster formats are supported like BIL, BIP, BSQ, ENVI, Erdas IMG, FGDBR, (Geo)TIFF, ...