Does not recommend this product
A very cool idea, but it seems to me that it only works if you have the SpoTwitter website open in a web browser. This means that if you do not have the site open (& logged in) your bio will not change along with your Spotify.
Your bio is supposed to go back to whatever you originally had it set as when you have no music playing, but I did not experience this in my short time with SpoTwitter (both with & without the SpoTwitter site open in a web browser.) This means that if you stop listening to music or close the SpoTwitter site your Twitter bio is stuck displaying whatever song SpoTwitter last logged.
As I said, I really think this is a great idea, but I cannot at this time recommend SpoTwitter until some improvements are made:
1. SpoTwitter must be able to operate without the need for the site to be open in a web browser.
2. SpoTwitter must more reliably change your bio back to its original state when no music is currently being played on your Spotify account.
3. Some customization options for how your music is displayed in your bio would be much appreciated. I do not like the emoji that SpoTwitter chooses to display next to your now playing music in your bio. It would also bring to opportunity to more clearly explain what the random song in your Twitter bio means (e.g., something as simple as adding "#NowPlaying" at the end of the bio.)