One of the highlighted features of CosmosSDK chains is the ability to transfer tokens permissionless to other chains in the network. This is also possible with Juno to and from other chains.
If you are just looking for a simple frontend to transfer tokens, Osmosis and Wynd Dex frontends both have deposit and withdraw UIs to do this. If you need to transfer tokens between Juno and another chain that does not have a frontend, or is new, you can use ibc-anywhere to seamlessly transfer between networks.
Typescript
If you wish to make a IBC transfer between chains, you will need to leverage cosmos directory & Cosmology's stack in your webapp.