A couple of notes first:
- Please read this tutorial to the end, including the "tweaking" section. 99% of people having transfer problems simply didn't follow the advice in that chapter. Please do.
- If you have an HTC or LG phone running Lollipop (android 5) make sure that you get version 4.14 of the ANT+ radio service from google play, because earlier versions don't work on your device.
Step 0: check you Android device
If your device is in that list, you can skip Step 1, as you won't need the ANT+ USB dongle. In Step 2, you need only the Radio Service (don't install other stuff). In most cases, it will come preinstalled. However, you have to set the "force ant+ scan" option in my app.
If your device is not in that list, chances are it does not come with a big, size A usb port, so you might wonder how to plug in your ant+ dongle. The answer is quite simple: you need an OTG cable like this:

An OTG connector is usually cheap (a couple of euros / dollars) and it's generally speaking quite useful. For instance, you can use it to connect a keyboard to your android device.
Some tablets (some Samsung, some Asus, etc) do not have a micro-usb, and require a manufacturer-specific OTG adapter.
Step 1: check your ANT+ USB key
The app is also known to work with the Suunto Movestick and with the newest "mini" ANT+ garmin dongles.
Step 2: install the ANT+ services
- The ANT Radio Service (which deals with ANT+ channels)
- The ANT USB Service (which deals with the USB key). If you have an internal ANT+ chip (like the Xperia) you don't need this. See here for details on using an Xperia.
Go ahead and do it!
Note that those apps require your Android device to be properly classified by Google Play as one with USB Host capabilities. Some devices, which are host-capable, are not properly classified in Google Play. In that case, unfortunately, the ANT+ services will result "incompatible" with your device and you won't be able to download them. As they're provided by Dynastream, there is little I can do about it - you'll have to find an alternative way to obtain and install the APK (or convince Dynastream to drop the USB HOST requirement from their manifest, as I did for Sportablet).
Step 3: check that everything works
If the dialog does not pop up, your USB key is not being recognized by the ANT+ Service. That's not part of Sportablet, so I can't really help you much on this side. Please check the Google Play page for the two ANT+ Service apps, as there are quite a few hints from users in the comments section.
Now, if you want to double-check that it works, and you have a chest strap that you use with your Garmin, you can also download the free ANT+ Demo from Dynastream. It's a simple app that can connect with a chest strap or a scale and show you some values (it won't connect with your Garmin, just with the HR belt). If the ANT+ Demo works, everything has been set up properly. If you don't have a chest strap, just skip this step.
Step 4: configure your watch
Choose Settings > ANT+ > Computer
Step 5: it's time to run Sportablet!
UPDATE (July 2014). Due to a new version of the Dynastream Service, before you click get new please get into the options, scroll down to the ANT+ section, scroll down to the last entry (it should read "Force Claim Interface") and turn that ON. This is usually needed only if you use the ANT+ USB dongle, and not necessary if you have a built-in ANT+ chip in your phone.
Now click the Get new button. You may see that the app is trying to connect on different frequencies: that's ok as it's part of the ANT+ protocol. After a while, the app will ask you to accept pairing on your device:
NOTE: if you're using an Xperia or another device with internal ANT+ chip, remember to click options, and set "Force ANT+ scan" on. This will force the app to try using the internal chip.
NOTE: it is often necessary to set up a few options in the app, as well as to set up your tablet / phone properly. So, if the process fails or times out, please read the following section. It is *very* important that you turn off wifi / data / 3g / etc on your android device.
Tweaking : )
ANT+ is not particularly good at transferring long sequences of data, and the protocol Garmin adopted on top of it for the 405/410 family does not allow to retry on failures, so the combination is a little flaky on some devices. If you have any problem downloading long activities, Sportablet and the Uploader provides a few settings that you can try (under "options")
- First, make sure that diagnostics is turned off. ANT+ is very time sensitive, and on some devices even the time spent on logging seems to cause problems.
- Next, just enable "Delay Ack". Leave all the other ANT+ options off. This should give the watch a little more time to synch with the tablet during long bursts.
- If that still fails, turn "Boost TX power" on.
- If you still have problems, get in touch. The other settings are not effective for a 405/410.