So after much requests, i have built a tiff to jpg converter mobile app and it can be downloaded on playstore. If you are looking for ways to convert you multi tiff files to jpg and png, then download the app below.

This TIFF to JPG converter can convert TIFF (Tagged Image File Format) files to JPG (JPEG Image) image.
How To Use:
Select a TIFF file (such as *.tiff, *.tif).
Click button "Convert" to start upload your file.
Once upload completed, converter will do the conversion

Download Tiff To Jpg Converter - https://play.google.com/store/apps/details?id=tiff.jpg.converter