With Converter App, you can convert 3GPP files into many other formats:
3GPP to MP4 | 3GPP to MP3 | 3GPP to MOV | 3GPP to WEBM | 3GPP to MKV | 3GPP to WAV | 3GPP to M4A | 3GPP to WMV
→ All 3GPP Converters
If you want to keep working with your final AVI, try:
AVI to MP4 | AVI to MP3 | AVI to MOV | AVI to MKV | AVI to WEBM | AVI to JPG | AVI to SRT | AVI to TEXT
→ All AVI Converters