[Samsung Galaxy R i9103] Nikhil:
Hi guys kindly list the apps which you use on SGR and consider them to be indispensable.

Kindly list them category wise if possible so as to make it easier for others to understand & find. Copy & paste the categories below and fill them up, if you feel anything is missing just post it here I'll add it to OP. :)

Here I am listing out all the best apps you use, category wise so that it becomes easy for you to find best app which suffice your needs.

★ Categories​

Audio Enhancement (app which enhances sound quality or plays with sound)

>ViPER4Android

>Voodoo Sound

>ACID Audio Engine​

Backup & Restore (Backup of Apps,Sms,Contacts)

>Super Backup

>Titanium Backup ★ root[Root]

>Carbon - Android App Sync and Backup

>Helium - App Sync and Backup

>GO Backup & Restore Pro​

Battery (All Battery Saving/Stats showing Apps)

-Battery Saving

>Greenify *ROOT: Renew my Phone[Root]

>JuiceDefender - battery saver​

-Battery Stats Showing

>Battery drain analyzer monitor

>BetterBatteryStats[Paid]

>GSam Battery Monitor​

Contacts (All contact related software; phone numbers,addresses,etc.)

>ExDialer & Contacts

>Contacts +​

Education (Any Kind of teaching,Information or educational Software)

>Flipboard: Your News Magazine

>ElectroDroid

>Offline dictionaries

>Dictionary - Merriam-Webster

>HowStuffWorks

>Justdial (JD)

>NewsHunt : India News | Jobs

>AntTek Dictionary

​

File Manager/Transfer (Apps dealing with file(s))

-Explorers

>ES File Explorer File Manager

>Solid Explorer

>X-plore File Manager

>File Expert

>AndroZip File Manager
​

-File Sharing

>SuperBeam | WiFi Direct Share

>AirDroid

>GL to SD(root)

>Fast File Transfer

>Hoccer: data sharing

>BubbleUPnP

>MediaHouse UPnP / DLNA Browser
​

GPS/Sensor (GPS applications, Sensor related apps)

>FasterFix

>Compass

>GPS Status & Toolbox

>GPS Essentials

>SpeedView: GPS Speedometer

>Android Sensor Box

>AndroSensor​

HomeScreen/Widgets (applications on your homescreen,mostly widgets,pie controls)

>Fancy Widgets

>ClockQ - Digital Clock Widget

>HD Widgets[Paid]

>BobClockD3

>Thousand Clock Widgets

>HomeFlip

>DashClock Widget

>Zooper Widget

>Creative Locker

>LMT Launcher

>Panoramic Screen

>Pie Control

>Galaxy S4 Lockscreen

>LG Optimus Lockscreen​

Imaging (apps that make use of your camera, camera effects,graphics programs)

>Camera360 Ultimate

>Fast Burst Camera Lite

>PicsArt - Photo Studio

>Sketch Me

>Cymera - Camera & Photo Editor

>500px

>PicSay - Photo Editor

>million moments -photo viewer

>PicSpeed HD Wallpapers 500,000​

Input (voice command,software keyboards, and other input applications)

>Google Keyboard

>SwiftKey Keyboard Free

>Speaktoit Assistant

>utter! Voice Commands BETA!​

Internet/Network (Browsers,messengers,download utilities)

-Browsers

>Dolphin Browser

>UC Browser for Android
​

-Networking/Messengers

>Facebook

>Twitter

>Skype - free IM & video calls

>WhatsApp Messenger

>Hangouts (replaces Talk)
​

-Download Managers

>tTorrent Lite - Torrent Client

>TubeMate YouTube Downloader

>Loader Droid download manager
​

​

Launchers (Best launchers)

>ReLaunch - Launcher

>SwipePad - Hyperspace Launcher

>Buzz Launcher

>Swapps! All Apps, Everywhere

>Action Launcher Pro

>Next Launcher 3D Lite Version

>Apex Launcher

>Aviate Alpha (Invite Only)

>Themer (Beta)​

Media (Video viewers,mp3 players,online TV,Screen Recorders)

>Poweramp Music Player (Trial)

>DicePlayer

>uSound Player (Stream Music)

>TuneIn Radio

>BS Player

>Shazam

>PlayerPro Music Player(trial)

>SCR Screen Recorder Free​

Messaging (All Sms/Mms related Apps)

>Sliding Messaging Free

>SMS Text Messaging ?PC Texting

>SnapPea

>GO SMS Pro​

Notifications (All Notification related apps)

>Control Center

>Floating Notifications (Trial)

>Android Updates, Tips & Apps(Drippler)
​

Office/Productivity (Document viewers, eBook readers,notes and presentation apps)

>Polaris Office 4.0

>Evernote

>Any.do To-do List & Task List​

Screen Sharing Apps (Team Viewer or Remotely Screen Sharing Apps)

>Phone Screen Sharing

>TeamViewer QuickSupport​

Security (call blocking,virus protection,anti-theft)

>Antivirus Security - FREE[Root]

>DroidWall - Android Firewall[Root]

>aeGis[Root]

>Cerberus anti theft[Paid][Root]

>Android Lost[Root]

>Bitdefender Antivirus Free​

System Tools/Flashing Tools (System tune-up,optimization,Monitor)

>Android Assistant(18 features)

>ROM Toolbox Lite[Root]

>Music Volume EQ

>Pimp My Rom (Beta)[Root]

>Clean Master (Cleaner)

>Auto Flasher ROM flash utility[Root]

>CPU Spy Reborn

>Tasker

>CPU-Z

>AutomateIt-Automate Your Droid

>Flashify (for root users)[Root]

>Clean Master (Cleaner) - FREE​

Other (anything that does not fit into one of the other categories)

>QuickMark Barcode Scanner

>JAYS Headset Control

>Headset Droid Trial

>1Tap Quick Bar -Quick Settings

>FaceLock for apps

>MediaFire

>Market Helper[Root]

>RoundR - Round Screen Corners

>Flash Alerts

>Gravity Screen Off

>Best Apps Market - for Android​

Kindly hit 'Thanks' if anyone who has posted here helped you. :)