I use several apps to show you how to achieve a nightime effect from a day time photograph using. I will cover blending and painting to achieve this effect. You will also need the app Frontview to straighten out the perspective.

Step 1  Original image taken using procamera

Step 2 Using Retouch. I removed the dark building on the upper left corner

Step 3 Using frontview, I corrected the perspective in the photo

Step 4 I added texture to darken the building using Iris

Step 5 Using photo fx, I changed the white wash sky to blue color

Step 6 I painted in the red neon light using paintbook

Step 7 I painted in the green neon light using paintbook

Step 8 I added some grow to the neon lights using lenslight and light

Step 9 Feeling the bottom of the image is too dark, I painted in some orange color using photofx

Step 10 I blended the image with image from step 8 to slightly bright the bottom of the image

Step 11 I added another texture to harmonize the image

Step 12 Feeling the bottom is too bright, I added some contrast to the bottom of the image using filterstorm. Here is my final image