PolkaBridge is a decentralized cross-chain protocol designed to act as the primary bridge between Polkadot and other blockchains. It will also introduce supporting DeFi features, to complement the bridging services. It currently operates on the Ethereum blockchain and is planning to migrate to the Polkadot blockchain, in the near future. Other chains support would be added in the future, as per the requirements.

The PBR token is the native asset of the PolkaBridge project. It exists primarily as a ERC-20 token on the Ethereum blockchain for now, but will be introduced on the Polkadot blockchain soon. It is required for:

1. Transactional activity on the network

2. As a staking collateral

3. For staking rewards 

4. For participation in the Launchpad IDOs

5. Base asset for cross-chain swaps

6. For lending and prediction purposes\ PolkaBridge platform modules include:

7. PolkaBridge Farming - a unique deflationary farming, which doesn't rely on inflation to reward stakers, but rather takes parts of every transaction as a deposit for the staking rewards pools. A certain part of every transaction is burned too.

8. PolkaBridge Launchpad - an Initial Decentralized Offering (IDO) platform, designed to incubate promising projects and to allow PBR holders to participate in early stage investment opportunities.