HBC was installed on my Japanese Wii with no problems. I've put apps on my SD card properly (named boot.dol and so on) but nothing happens when I load the HBC. I only see the bubbles. Any suggestions? Just to clarify, Homebrew Channel works fine and my Wii is version 3.4J if that makes any difference. Thanks for the help!

In order to make an application appear in the Homebrew Channel, you must do the following:
1. Make a folder on the root of your SD card called "apps".
Note: This is case-sensitive; Make sure it is not "APPS".
2. In the folder "apps," create a folder for the application (for example, "/apps/Homebrew Browser/").
3. Copy the files for the application into its folder (e.g. /apps/Homebrew Browser/).
4. Find the executable file (either .elf or .dol) and rename it to boot.dol (or boot.elf if it was an .elf file) if it is not already named that (for example /apps/Homebrew Browser/boot.dol). If the app comes with an icon.png and meta.xml, copy the them both into the the same folder as the app's boot.dol.

I have done all of that, but nothing comes up. I even tried again with Wii Brew SD Installer but still nothing comes up. Any ideas? Is it because my system is 3.4J?

Are you sure you have it correctly?
On your computer it should appear as, SD:\apps\Homebrew Browser\boot.dol
or maybe you could try a different SD card

Well, it seems to be working now. I'm not too sure what was wrong before. All I did was delete everything on the SD card and reinstall it. Anyway, thanks for the help!

No problem. If you've got any other questions or anything, feel free to ask.