DroidBridge

A two-pane file browser: your Mac on one side, an Android phone on the other, using the bundled adb tools. Switch between internal storage and an SD card, follow the transfer, and see a plain-language note when a drive is read-only, such as NTFS.

DroidBridge is made by Alpha Tembo in Harare. It is for Mac and Android. Try it free for 3 days, then one activation code runs it on one Mac. US$19 once.

US$19 for one Mac, after a 3-day trial.