Here you will find some free standalone utilities that may prove helpful in studying the works of Shrii Prabhat Ranjan Sarkar.
S4 Sanskrit Dictionary
This application lets you look up the meaning of 140,000 Sanskrit words with searches in any of 4 scripts: Shrii Sarkar’s Roman Saḿskrta, Devanagari, Bengali, or IAST.
Download for a Windows PC
Download for a Mac
For help installing an app not got on Apple’s App Store, see here.