In an interview, when asked what some of their favorite VST / FX Racks are, Odesza reply, "Right now, my go to is Soundtoys. They have the best delay I’ve ever used..." (original interview here). The EchoBoy is SountToys' most renown delay plugin, so it can be assumed this is the one referenced by Odesza despite them not naming it exactly.

In this tweet from the Being Funny In A Foreign Language listening party, in regards to the question: "Slapback on Mattys vocal [on Oh Caroline]?", George responds, "Echo boy two different delay times", and also replies, "Echoboy" to another question asking the one soundtoys plug in he couldn't live without.

Used for "Get On Your Boots".

Most of Bono's vocals were recorded through a Shure Beta 58 dynamic mic, with some EQ (including the Waves VEQ3, top) and heavy compression from the Fairchild 660 plug-in. No reverb was used, but Sound Toys' Echo Boy provided delay.

An image of the settings can be found here.

Used on "Sex on Fire", as stated by Only by the Night producer Jacquire King in this December 2008 Sound on Sound interview. An image of the settings can be found here.

• Bass: AMS delay, Sound Toys Echoboy, Empirical Labs Distressor, Chandler TG1, Dbx Disco Boombox

"On the Mix window screen you can see that there are bass DI, bass amp, bass AMS and bass delay tracks. The AMS is a delay that I applied at Blackbird and that I then printed to Pro Tools. The delay is the Echoboy delay, which I added during mixing. The idea was to get a different texture than I could with the AMS delay. Both delays had different delay times, different qualities of sound, and different feedback and modulation effects, and the idea was to spread them out and fatten up the sound, give it some space without putting a reverb or something poky–sounding on it. By spreading the bass out a bit you also make it sound bigger. In addition, there's some Distressor and TG1 compression and some EQ on the bass, as well as some more subharmonic synthesis, again using the DBX Disco Boombox. I have a slightly more modern version of the box."

The item can be seen as a Pro Tools mix channel label in this image from the same interview.

The final Pro Tools Session included four bass tracks: the original miked and DI'd recordings, and duplicates treated with AMS hardware and Sound Toys (right) software delays.

At the 3:12 mark of the video Goransson explains his use of the Echoboy on Childish Gambino's "Redbone"

In the "ILLENIUM Production Livestream" on YouTube, Illenium uses the Soundtoys EchoBoy Analog Echo Processor, showcasing its role in his production process.

Used for Beyoncé's feature on Coldplay's "Hymn for the Weekend", as mentioned by A Head Full of Dreams co-producer Rik Simpson in this Sound on Sound article.

At the bottom of the session are the Beyoncé vocal tracks, on which I mainly used the SSL E Channel strip, UBK1, L2, SoundToys Echo Boy, Avid ModDelay and the QL Space.”

He uses SoundToys' EchoBoy for delays, clearly stated at 10:08 You can also see an instance of the plugin at 11:42 in another track, so I think he uses this plugin quite often.

5min 29 second mark you can see the Echo Boy on the attached video.

Used on "APESHIT", as stated by producer Stuart White in this September 2018 Sound on Sound interview.

The first four aux tracks feature SoundToys effects, namely Little Microshift, two EchoBoy delays, and a delay from the Little PrimalTap. Next are a Hall Reverb aux and a Church Reverb aux, both using Waves’ RVerb, an EMT plate from Audio Ease’s Altiverb, four aux tracks with the Waves H-Delay and various other plug-ins on them as well, and four more reverb auxes with the Avid Revibe II, two Avid D-Verbs and another RVerb.

White: “I use the Little Microshift in pretty much every mix, with the left-right micro pitch-shift effect that’s similar to the classic effect in the Eventide H3000 shift where you pitch one side down six cents and one side up six cents to create width. It’s a good way to get your vocals wider without them being out of phase. It thickens up vocals, and is kind of like a doubler. I do quite a lot of filtering on some of the EchoBoy delays, for example with the Waves REQ, and I am adding colour with the SoundToys Devil-Loc, which is great if you want to colour the delay so it is separate from the main vocal, and compress it with the UAD LA3A and mix that in to taste.”

(...) Jay-Z’s part consists of just two tracks, one lead, and one ad-lib, with an additional ‘reverse’ track, and a ‘jay clean’ track. White: “The main lead vocal track has the SSL E0-channel, Waves C4 multiband compressor for some control, FabFilter Pro-Q2 EQ, with a few notches, and McDSP AE400. Where Jay raps ‘Tell the Grammy’s fuck that 0 for 8 shit / have you ever seen a crowd goin’ apeshit?’, you can hear some stuff in the background, which is another example of me adding flair and energy. That actually comes from the third ‘Voice Sample’ track further up the session, on which I have some automated plug-ins, the ReVibe, Waves S1 Imager, and filter sweep from the EQ3. It’s subtle, but it gives you a little ear candy.”

In this youtube video at 6:16 Vitalic talking about Echoboy.

"And I do use a lot of plugins too for effects. I love EchoBoy. That’s been one of my favorite plugins for a long time. I think that’s actually the biggest bang for your buck out there on the Internet because the thing only costs $179. And not only does it give you every delay known to man, but it gives you amazing special effects. It’s a great, great plugin." - Henderson about SoundToys EchoBoy.