I recommend that you install this mod using Long War Mod Manager (http://www.nexusmods.com/xcom/mods/620/?). Alternatively you can use PatcherGUI 7.1 or better if you wish.

Tested with Long War beta 15d2/15e/15f/1.0. It should work with any version of beta 15 or better.

Main features:

• Displays Soldier XP / Psi XP
• XP values take mission completion bonuses into account
• Displays Soldier's current mobility and damage reduction
• Displays a count of active aliens for each alien type
• Displays a count of aliens killed (in total, not just for the selected soldier)
• XP earned for each kill will appear over the dead alien
  

This mod displays soldier XP/PsiXP, mobility, damage reduction and active alien counts on the soldier info screen during battle (F1). Psi XP is only displayed for soldiers with Psi Rank greater than 0. The text labels (Health, Will, etc) have been replaced with icons so the screen looks nicer too.

Unlike other similar mods that display soldier XP, this version takes into account any bonus XP that the soldier will qualify for when the mission completes, so the "level up" indicator (the plus "+" sign to the left of the soldier's name) on the main battlefield HUD will light up correctly if the soldier will be promoted at the end of the mission. You no longer have to guess if a rookie will get promoted or not. Any PsiXP mission completion bonuses are included as well. 

A count of active aliens for each alien type is displayed under the soldier's name. An alien becomes active once it makes contact with the squad. Now you can be sure that you've completely cleared out a pod of aliens before moving your soldiers into possibly risky positions.

(If you like this mod then also try out my "Show Soldier XP" mod which displays soldier xp on the soldier selection table).

This mod's bonus XP calculation uses the same internal functions used by the game so it is 100% accurate. The soldiers "real" XP value is not actually changed, so there's no risk of XP being awarded incorrectly.

For the curious, mission bonus XP (awarded at the end of the mission) is calculated by the game as follows:

STANDARD MISSIONS
 - Mission Complete: +80 xp
 - Soldier saw a "special" alien (e.g. Outsider): +30xp

SPECIAL MISSIONS (e.g. Council missions, etc).
 - Mission Complete: +120 xp
 - Soldier saw a "high level" alien (e.g. Outsider): +60xp

NO DEATH BONUS
 - No soldiers died on the mission: +20xp

If a soldier dies then the "no death" bonus will not be included in the XP amount displayed. The level up indicator will disappear if the XP now falls below the required XP to reach the next rank.

COVERT EXTRACTIONS
 - Covert operative gets an additional +120xp

Any special items or effects are also taken into account (e.g. extra XP for officers with medals that add bonus XP, etc.)

VERSIONS
1.0a - Initial release
1.0b - Updated to take dynamic war settings into account (mission bonus xp is now correctly scaled according to dynamic war setting)
1.0c - Updated so that the "Trooper X has earned a promotion" message now also takes mission bonus xp into account.
1.0d - Active alien counts are now displayed under the soldier's name. Added current damage reduction value to soldier stats.
1.0e - Active alien counts should now also display when a SHIV is selected. Tweaked DR calculation to remove randomness when used with this mod (does not affect the rest of the game). DR value displayed will now be the minimum (assuming not flanked, etc).
1.0f - "No death" mission bonus should actually be "No dead or critically injured soldiers". Bonus XP will no longer be included if there are any critically wounded soldiers.
1.0g - XP for covert operative now also taken into account. DR value calculation updated. Previously it would display very large values when percentage based DR was in use (e.g. by MECs). If % based DR is in use then it will now display the amount of damage that will be absorbed for an incoming damage value of 12.
1.0h - Added "Aliens Killed" count to info screen. This shows the total number of aliens killed in the mission so far. XP earned per kill will appear over the dead alien ("+22XP")