SLPJS is an all-in-one high level solution for creating SLP transactions.
SLP-Validate makes it easy to validate tokens using a variety of methods.
SLP-List lists addresses and balances at different block heights. This is normally used for dividend applications.
bchaddrjs-SLP let's you validate and convert between different address formats including of course simpleledger addresses.
slp-parser is a low level library for parsing SLP OP_RETURN metadata.
slp-metadatamaker is a low level library for creating SLP OP_RETURN metadata.