How can I browse mempool in Ethereum? Is it possible from EthereumJ or on some websites?
To me, etherchain is more accurate to show the pending transactions. https://www.etherchain.org/txs/pending.
It is possible to get the pending transaction in JSON through the following get request: https://www.etherchain.org/txs/data?draw=1&start=0&length=100
New answer September 2020
A cool new tool was released: https://explorer.blocknative.com
Another visualisation, why breakdown into gas price ranges. Displays total gas costs and count of pending transactions.