Reading the very first line on Google Play for Shark Reader
Application for reading pcap files.
Which implies the OP needs some tool to generate pcap files..also, reading this also on Google Play for Shark for root
Traffic sniffer, works on 3G and WiFi (works on FroYo tethered mode too). To open dump use WireShark or similar software, for preview dump
on phone use Shark Reader. Based on tcpdump. Please leave
comments/send e-mail if you have any problems/suggestions.
Bolded sentence is my emphasis, so it seems a bit confusing and mis-leading. From the description on the Play Store, it is saying that using WireShark is a pre-requisite for Shark Reader to work..but cannot find the actual app called the same.
There is one available for desktop PC's to allow sniffing of ethernet traffic, but for Android, remains to be seen.
Also, for what its worth, sniffing traffic on 3G is questionable as that's dependent on if the radio base-band allows promiscuous mode, that's a given in order to be able to sniff traffic, even though its unlikely, due to proprietary nature of radio firmware..)
Wifi on the other hand, is extremely dependent of the capability of sniffing also, not all of them have the capability to go into promiscuous mode, again mileage will vary depending on the Wifi chipset/driver and kernel regardless if rooted.