Without having much to compare to, this app takes seemingly accurate bpm. Ive been using for a few days and it seems like its temperamental. Sometimes it takes you pulse and others you are just patiently waiting for it to not take your pulse. Which is frustrating.
Also frustrated with the tagging option. When i tick the meter to mark my pulse, it never records my tick. I wish you could make your own tags and collect notes.
Overall, if you are interested in taking your pulse once in a while, this app should be enough for you. If you are conducting experiments (arthur coca) or need to collect other data along with pulse, this app is probably not gonna be helpful enough.